RESUMO
A pulsed sextupole magnet was used for beam injection at the KEK-Photon Factory (KEK-PF). During the top-up injection, oscillation of the stored beam was observed. To investigate this issue, a compact pick-up probe has been developed for measuring peak fields around the zero-magnetic-field region where the stored beam passes. The probe has two coils: a main coil and a background coil. The width and length of the main coil are only 3.2 and 5.8 mm, respectively. The voltage signal from the background coil is subtracted from that of the main coil to obtain an effective voltage signal. The results show that the peak field of a pulsed magnet can be measured with a sufficient accuracy for magnetic field mapping. A magnetic field signal with an amplitude of 2.2 × 10-4 T was measured clearly. The longitudinal field structure that contains the magnetic field generated by the eddy-current effect was observed, which explains the oscillation of the stored beam at the KEK-PF.
RESUMO
A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.
RESUMO
Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu(micro)<-->nu(tau) neutrino oscillation parameters; 1.9x10(-3)